/**
 * Loads a Wavefront .mtl file specifying materials
 *
 * @author angelxuanchang
 */

THREE.MTLLoader = function (manager){

    this.manager = (manager !== undefined) ? manager : THREE.DefaultLoadingManager;

};

THREE.MTLLoader.prototype = {

    constructor: THREE.MTLLoader,

    /**
	 * Loads and parses a MTL asset from a URL.
	 *
	 * @param {String} url - URL to the MTL file.
	 * @param {Function} [onLoad] - Callback invoked with the loaded object.
	 * @param {Function} [onProgress] - Callback for download progress.
	 * @param {Function} [onError] - Callback for download errors.
	 *
	 * @see setPath setTexturePath
	 *
	 * @note In order for relative texture references to resolve correctly
	 * you must call setPath and/or setTexturePath explicitly prior to load.
	 */
    load: function (url, onLoad, onProgress, onError)
    {

        var scope = this;

        var loader = new THREE.FileLoader(this.manager);
        loader.setPath(this.path);
        loader.load(url, function (text)
        {

            onLoad(scope.parse(text));

        }, onProgress, onError);

    },

    /**
	 * Set base path for resolving references.
	 * If set this path will be prepended to each loaded and found reference.
	 *
	 * @see setTexturePath
	 * @param {String} path
	 *
	 * @example
	 *     mtlLoader.setPath( 'assets/obj/' );
	 *     mtlLoader.load( 'my.mtl', ... );
	 */
    setPath: function (path)
    {

        this.path = path;

    },

    /**
	 * Set base path for resolving texture references.
	 * If set this path will be prepended found texture reference.
	 * If not set and setPath is, it will be used as texture base path.
	 *
	 * @see setPath
	 * @param {String} path
	 *
	 * @example
	 *     mtlLoader.setPath( 'assets/obj/' );
	 *     mtlLoader.setTexturePath( 'assets/textures/' );
	 *     mtlLoader.load( 'my.mtl', ... );
	 */
    setTexturePath: function (path)
    {

        this.texturePath = path;

    },

    setBaseUrl: function (path)
    {

        console.warn('THREE.MTLLoader: .setBaseUrl() is deprecated. Use .setTexturePath( path ) for texture path or .setPath( path ) for general base path instead.');

        this.setTexturePath(path);

    },

    setCrossOrigin: function (value)
    {

        this.crossOrigin = value;

    },

    setMaterialOptions: function (value)
    {

        this.materialOptions = value;

    },

    /**
	 * Parses a MTL file.
	 *
	 * @param {String} text - Content of MTL file
	 * @return {THREE.MTLLoader.MaterialCreator}
	 *
	 * @see setPath setTexturePath
	 *
	 * @note In order for relative texture references to resolve correctly
	 * you must call setPath and/or setTexturePath explicitly prior to parse.
	 */
    parse: function (text)
    {

        var lines = text.split('\n');
        var info = {};
        var delimiter_pattern = /\s+/;
        var materialsInfo = {};

        for (var i = 0; i < lines.length; i++)
        {

            var line = lines[i];
            line = line.trim();

            if (line.length === 0 || line.charAt(0) === '#')
            {

                // Blank line or comment ignore
                continue;

            }

            var pos = line.indexOf(' ');

            var key = (pos >= 0) ? line.substring(0, pos) : line;
            key = key.toLowerCase();

            var value = (pos >= 0) ? line.substring(pos + 1) : '';
            value = value.trim();

            if (key === 'newmtl')
            {

                // New material

                info = { name: value };
                materialsInfo[value] = info;

            } else if (info)
            {

                if (key === 'ka' || key === 'kd' || key === 'ks')
                {

                    var ss = value.split(delimiter_pattern, 3);
                    info[key] = [parseFloat(ss[0]), parseFloat(ss[1]), parseFloat(ss[2])];

                } else
                {

                    info[key] = value;

                }

            }

        }

        var materialCreator = new THREE.MTLLoader.MaterialCreator(this.texturePath || this.path, this.materialOptions);
        materialCreator.setCrossOrigin(this.crossOrigin);
        materialCreator.setManager(this.manager);
        materialCreator.setMaterials(materialsInfo);
        return materialCreator;

    }

};

/**
 * Create a new THREE-MTLLoader.MaterialCreator
 * @param baseUrl - Url relative to which textures are loaded
 * @param options - Set of options on how to construct the materials
 *                  side: Which side to apply the material
 *                        THREE.FrontSide (default), THREE.BackSide, THREE.DoubleSide
 *                  wrap: What type of wrapping to apply for textures
 *                        THREE.RepeatWrapping (default), THREE.ClampToEdgeWrapping, THREE.MirroredRepeatWrapping
 *                  normalizeRGB: RGBs need to be normalized to 0-1 from 0-255
 *                                Default: false, assumed to be already normalized
 *                  ignoreZeroRGBs: Ignore values of RGBs (Ka,Kd,Ks) that are all 0's
 *                                  Default: false
 * @constructor
 */

THREE.MTLLoader.MaterialCreator = function (baseUrl, options)
{

    this.baseUrl = baseUrl || '';
    this.options = options;
    this.materialsInfo = {};
    this.materials = {};
    this.materialsArray = [];
    this.nameLookup = {};

    this.side = (this.options && this.options.side) ? this.options.side : THREE.FrontSide;
    this.wrap = (this.options && this.options.wrap) ? this.options.wrap : THREE.RepeatWrapping;

};

THREE.MTLLoader.MaterialCreator.prototype = {

    constructor: THREE.MTLLoader.MaterialCreator,

    crossOrigin: 'Anonymous',

    setCrossOrigin: function (value)
    {

        this.crossOrigin = value;

    },

    setManager: function (value)
    {

        this.manager = value;

    },

    setMaterials: function (materialsInfo)
    {

        this.materialsInfo = this.convert(materialsInfo);
        this.materials = {};
        this.materialsArray = [];
        this.nameLookup = {};

    },

    convert: function (materialsInfo)
    {

        if (!this.options) return materialsInfo;

        var converted = {};

        for (var mn in materialsInfo)
        {

            // Convert materials info into normalized form based on options

            var mat = materialsInfo[mn];

            var covmat = {};

            converted[mn] = covmat;

            for (var prop in mat)
            {

                var save = true;
                var value = mat[prop];
                var lprop = prop.toLowerCase();

                switch (lprop)
                {

                    case 'kd':
                    case 'ka':
                    case 'ks':

                        // Diffuse color (color under white light) using RGB values

                        if (this.options && this.options.normalizeRGB)
                        {

                            value = [value[0] / 255, value[1] / 255, value[2] / 255];

                        }

                        if (this.options && this.options.ignoreZeroRGBs)
                        {

                            if (value[0] === 0 && value[1] === 0 && value[2] === 0)
                            {

                                // ignore

                                save = false;

                            }

                        }

                        break;

                    default:

                        break;

                }

                if (save)
                {

                    covmat[lprop] = value;

                }

            }

        }

        return converted;

    },

    preload: function ()
    {

        for (var mn in this.materialsInfo)
        {

            this.create(mn);

        }

    },

    getIndex: function (materialName)
    {

        return this.nameLookup[materialName];

    },

    getAsArray: function ()
    {

        var index = 0;

        for (var mn in this.materialsInfo)
        {

            this.materialsArray[index] = this.create(mn);
            this.nameLookup[mn] = index;
            index++;

        }

        return this.materialsArray;

    },

    create: function (materialName)
    {

        if (this.materials[materialName] === undefined)
        {

            this.createMaterial_(materialName);

        }

        return this.materials[materialName];

    },

    createMaterial_: function (materialName)
    {

        // Create material

        var scope = this;
        var mat = this.materialsInfo[materialName];
        var params = {

            name: materialName,
            side: this.side

        };

        function resolveURL(baseUrl, url)
        {

            if (typeof url !== 'string' || url === '')
                return '';

            // Absolute URL
            if (/^https?:\/\//i.test(url)) return url;

            return baseUrl + url;

        }

        function setMapForType(mapType, value)
        {

            if (params[mapType]) return; // Keep the first encountered texture

            var texParams = scope.getTextureParams(value, params);
            var map = scope.loadTexture(resolveURL(scope.baseUrl, texParams.url));

            map.repeat.copy(texParams.scale);
            map.offset.copy(texParams.offset);

            map.wrapS = scope.wrap;
            map.wrapT = scope.wrap;

            params[mapType] = map;

        }

        for (var prop in mat)
        {

            var value = mat[prop];
            var n;

            if (value === '') continue;

            switch (prop.toLowerCase())
            {

                // Ns is material specular exponent

                case 'kd':

                    // Diffuse color (color under white light) using RGB values

                    params.color = new THREE.Color().fromArray(value);

                    break;

                case 'ks':

                    // Specular color (color when light is reflected from shiny surface) using RGB values
                    params.specular = new THREE.Color().fromArray(value);

                    break;

                case 'map_kd':

                    // Diffuse texture map

                    setMapForType("map", value);

                    break;

                case 'map_ks':

                    // Specular map

                    setMapForType("specularMap", value);

                    break;

                case 'norm':

                    setMapForType("normalMap", value);

                    break;

                case 'map_bump':
                case 'bump':

                    // Bump texture map

                    setMapForType("bumpMap", value);

                    break;

                case 'ns':

                    // The specular exponent (defines the focus of the specular highlight)
                    // A high exponent results in a tight, concentrated highlight. Ns values normally range from 0 to 1000.

                    params.shininess = parseFloat(value);

                    break;

                case 'd':
                    n = parseFloat(value);

                    if (n < 1)
                    {

                        params.opacity = n;
                        params.transparent = true;

                    }

                    break;

                case 'tr':
                    n = parseFloat(value);

                    if (n > 0)
                    {

                        params.opacity = 1 - n;
                        params.transparent = true;

                    }

                    break;

                default:
                    break;

            }

        }

        this.materials[materialName] = new THREE.MeshPhongMaterial(params);
        return this.materials[materialName];

    },

    getTextureParams: function (value, matParams)
    {

        var texParams = {

            scale: new THREE.Vector2(1, 1),
            offset: new THREE.Vector2(0, 0)

        };

        var items = value.split(/\s+/);
        var pos;

        pos = items.indexOf('-bm');

        if (pos >= 0)
        {

            matParams.bumpScale = parseFloat(items[pos + 1]);
            items.splice(pos, 2);

        }

        pos = items.indexOf('-s');

        if (pos >= 0)
        {

            texParams.scale.set(parseFloat(items[pos + 1]), parseFloat(items[pos + 2]));
            items.splice(pos, 4); // we expect 3 parameters here!

        }

        pos = items.indexOf('-o');

        if (pos >= 0)
        {

            texParams.offset.set(parseFloat(items[pos + 1]), parseFloat(items[pos + 2]));
            items.splice(pos, 4); // we expect 3 parameters here!

        }

        texParams.url = items.join(' ').trim();
        return texParams;

    },

    loadTexture: function (url, mapping, onLoad, onProgress, onError)
    {

        var texture;
        var loader = THREE.Loader.Handlers.get(url);
        var manager = (this.manager !== undefined) ? this.manager : THREE.DefaultLoadingManager;

        if (loader === null)
        {

            loader = new THREE.TextureLoader(manager);

        }

        if (loader.setCrossOrigin) loader.setCrossOrigin(this.crossOrigin);
        texture = loader.load(url, onLoad, onProgress, onError);

        if (mapping !== undefined) texture.mapping = mapping;

        return texture;

    }

};
